Data output apparatus and data output method

ABSTRACT

A data output apparatus is provided. The data output apparatus includes a playback unit and an audio processing unit. The playback unit carries out playback of data at 2x speed from a tape-shaped recording medium, on which has been recorded video data with a field frequency of 59.94 Hz and audio data with a sampling frequency of 48 kHz, by playing back video data in odd-numbered fields and audio data corresponding thereto and video data in even-numbered fields and audio data corresponding thereto in parallel. The audio processing unit writes the audio data corresponding to the odd-numbered fields and the audio data corresponding to the even-numbered fields played back in parallel in the playback unit into a memory, reads out the audio data from the memory at 96 kHz in order of the corresponding fields, and outputs the audio data to dual-link HD-SDI transmitters.

CROSS REFERENCES TO RELATED APPLICATIONS

The present invention contains subject matter related to Japanese PatentApplication JP 2007-263620 filed in the Japanese Patent Office on Oct.9, 2007, the entire contents of which being incorporated herein byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a data output apparatus and data outputmethod when playing back data at 2× speed in VTRs.

2. Description of the Related Art

HDCAM SR® format that has been proposed by the present applicant is aVTR format compliant with full high vision video with a resolution of1920H×1080V. According to HDCAM SR® format, a recording region for videodata of one field is divided into a start region and an end region ofeach track and a recording region for audio data of one field isprovided in between such regions. The sampling frequency of the audiodata is 48 kHz. Twelve channels are provided for audio data, and data onthe first channel to the twelfth channel is recorded in that order inthe recording region for audio data of one field.

When recording video data with a field frequency of 59.94 Hz, thesampling rate of the audio data is not an integer multiple of the fieldfrequency and the number of samples of audio data in one field iscalculated as (1/59.94 Hz)/(1/48 kHz)=800.8.

As shown in FIG. 1, in such a case, data is handled in units of fiveconsecutive fields and “audio1(800)” with 800 samples is recordedcorresponding to the video data “picture1” of the first field and audiodata “audio2(801)” to “audio5(801)” that each have 801 samples arerecorded corresponding to the video data “picture2” to “picture5” of thesecond to fifth fields.

FIG. 2 is a diagram showing the recording positions of the video data“picture1” to “picture5” and the audio data “audio1(800)” to“audio5(801)” on a magnetic tape. The video data “picture1” of the firstfield is divided into the start region and end region of the track (thedivided two pieces of video data are indicated in FIG. 2 as “picture1(1/2)” and “picture1 (2/2)”) and the audio data “audio1(800)” isrecorded in the space between such regions. The same also applies to thesecond to fifth fields. Note that although the case where the video dataof one field is recorded on only one track is shown for convenience inFIG. 2, the video data of one field is actually recorded using twelvetracks.

Although not shown in FIG. 2, start signals showing the start of dataare recorded before the respective recording positions of the video data“picture1” to “picture5” (i.e., at the first positions read by amagnetic head). Also, “5-field” IDs that identify the ordinal positionsof the respective audio data that form a five-field unit are recordedbefore the respective recording positions of the audio data“audio1(800)” to “audio5(801)”, thereby making it possible to identifywhether the respective audio data have 800 or 801 samples. Such“5-field” IDs take the values 0 to 4, with the value 0 showing the audiodata corresponding to the first field where the number of samples is 800and the values 1, 2, 3, and 4 showing the audio data corresponding tothe second, third, fourth, and fifth fields where the number of samplesis 801.

According to HDCAM SR® format, 1× speed mode (where the data rate ofvideo data is 440 Mbps) and 2× speed mode (where the data rate of videodata is 880 Mbps) are supported as recording and playback modes.Accordingly, it is possible to play back data, which was recorded at 1×speed, at 1× speed and also possible to play back data, which wasrecorded at 1× speed, at 2× speed.

1× Speed Playback

FIG. 3 is a block diagram showing an output system for audio data in anHDCAM SR®-format video tape recorder where video data with a fieldfrequency of 59.94 Hz is played back at 1× speed and transmitted as anHD-SDI signal according to SMPTE 292M. After waveform shaping and adecoding process have been carried out in a decoding unit 20 on thesignal read out from a magnetic tape TP by a playback head PB, errorcorrection is carried out in a ECC decoder 21. Subsequently, audio datathat has been subjected to error correction is outputted from the ECCdecoder 21 to an audio processor 22.

The audio processor 22 outputs the audio data to an HD-SDI transmitter23 as audio data to be embedded in video data.

FIGS. 4A and 4B are diagrams showing audio data outputted from the ECCdecoder 21 and audio data outputted from the HD-SDI transmitter 23. Asshown in FIG. 4A, audio data that was consecutive in the original audio,such as “audio1(800)”, “audio2(801)”, “audio3(801)”, “audio4(801)”,“audio5(801)”, . . . is outputted from the ECC decoder 21 to the audioprocessor 22.

The audio processor 22 outputs such audio data in the same order of“audio1(800)”, “audio2(801)”, “audio3(801)”, “audio4(801)”,“audio5(801)”, . . . to the HD-SDI transmitter 23. As shown in FIG. 4B,although the audio data outputted from the HD-SDI transmitter 23 isembedded into spaces between the video data and therefore appears to bedivided into field units, the data is still consecutive in the originalorder of “audio1(800)”, “audio2(801)”, “audio3(801)”, “audio4(801)”,“audio5(801)”, . . . .

FIG. 5 is a diagram showing details of the channels of audio dataoutputted from the audio processor 22. Here, it is possible to embedsixteen channels of audio data in an HD-SDI signal. The HD-SDItransmitter 23 is therefore provided with eight input terminals I1 to 18for inputting sixteen channels of audio data. The audio processor 22outputs audio data on two channels in each sampling period to six inputterminals I1 to I6 out of the eight input terminals.

Specifically, the audio processor 22 outputs the audio data as shownbelow to the input terminals I1 to I6 in a given sampling period SC1.

-   -   ch1_0 that is part of the data on channel ch1 and ch2_0 that is        part of the data on channel ch2 are outputted to the input        terminal I1.    -   ch3_0 that is part of the data on channel ch3 and ch4_0 that is        part of the data on channel ch4 are outputted to the input        terminal I2.    -   ch5_0 that is part of the data on channel ch5 and ch6_0 that is        part of the data on channel ch6 are outputted to the input        terminal I3.    -   ch7_0 that is part of the data on channel ch7 and ch8_0 that is        part of the data on channel ch8 are outputted to the input        terminal I4.    -   ch9_0 that is part of the data on channel ch9 and ch10_0 that is        part of the data on channel ch10 are outputted to the input        terminal I5.    -   ch11_0 that is part of the data on channel ch11 and ch12_0 that        is part of the data on channel ch12 are outputted to the input        terminal I6.

The audio processor 22 outputs the following audio data to the inputterminals I1 to I6 in the next sampling period SC2.

-   -   ch1_1 that follows ch1_0 in the data on channel ch1 and ch2_1        that follows ch2_0 in the data on channel ch2 are outputted to        the input terminal I1.    -   ch3_1 that follows ch3_0 in the data on channel ch3 and ch4_1        that follows ch4_0 in the data on channel ch4 are outputted to        the input terminal I2.    -   ch5_1 that follows ch5_0 in the data on channel ch5 and ch6_1        that follows ch6_0 in the data on channel ch6 are outputted to        the input terminal I3.    -   ch7_1 that follows ch7_0 in the data on channel ch7 and ch8_1        that follows ch8_0 in the data on channel ch8 are outputted to        the input terminal I4.    -   ch9_1 that follows ch9_0 in the data on channel ch9 and ch10_1        that follows ch10_0 in the data on channel ch10 are outputted to        the input terminal I5.    -   ch11_1 that follows ch11_0 in the data on channel ch11 and        ch12_1 that follows ch12_0 in the data on channel ch12 are        outputted to the input terminal I6.

In the same way, in each sampling period, data on the channels ch1 andch2 is outputted as a unit to the input terminal I1, data on thechannels ch3 and ch4 is outputted as a unit to the input terminal I2,data on the channels ch5 and ch6 is outputted as a unit to the inputterminal I3, data on the channels ch7 and ch8 is outputted as a unit tothe input terminal I4, data on the channels ch9 and ch10 is outputted asa unit to the input terminal I5, and data on the channels ch11 and ch12is outputted as a unit to the input terminal I6.

×2 Speed Playback

An example where 1× speed playback is carried out has been describedabove. Next, an example where data recorded at 1× speed is played backat 2× speed is described. In the case where video data played back at 2×speed is transmitted as an HD-SDI signal, a LINK-A HD-SDI transmitterand a LINK-B HD-SDI transmitter that comply to dual-link HD-SDI asstandardized in SMPTE 372M (see SMPTE 372M PROPOSED SMPTE STANDARD forTelevision—Dual LINK 292M Interface for 1920×1080 Picture Raster) arerequired.

SUMMARY OF THE INVENTION

FIG. 6 is a block diagram showing an output system for audio data in anHDCAM®-format VTR in the case where video data with a field frequency of59.94 Hz is played back at 2× speed and transmitted as an HD-SDI signal.Parts of this system that are the same as in the configuration shown inFIG. 3 described above have been assigned the same reference numerals.

The rotational speed of a rotating drum (not shown) that drives amagnetic tape TP is set at double the speed during 1× speed playback.The signal read out from the magnetic tape TP at 2× speed by theplayback head PB is divided by a switch 10 into signals from recordingtracks for data in odd-numbered fields (“picture1” and “audio1(800)”,“picture3” and “audio3(801)”, and “picture5” and “audio5(801)” shown inFIGS. 1 and 2 described above) and signals from recording tracks fordata in even-numbered fields (“picture2” and “audio2(801)” and‘picture4’ and “audio4(801)” shown in FIGS. 1 and 2 described above) andsuch signals are written into a cache memory 11-1 and a cache memory11-2.

The signals written into the cache memories 11-1, 11-2 are convertedinto 1× speed signals by reading the signals from the cache memories11-1, 11-2 at one half of the rate used when writing the signals.

The 1× speed signals from the cache memories 11-1, 11-2 are subjected towave-shaping and decoding processes in decoding units 20-1, 20-2respectively (the configuration of such decoding units is the same asthe decoding unit 20 shown in FIG. 3), and are then subjected to errorcorrection in ECC decoders 21-1, 21-2 respectively (the configuration ofsuch decoders is the same as the ECC decoder 21 shown in FIG. 3).

Audio data that has been subjected to error correction is outputted fromthe ECC decoders 21-1, 21-2 to an audio processor 12. By doing so, audiodata that has been played back at 2× speed by playing back video data ofodd-numbered fields and audio data corresponding thereto and video dataof even-numbered fields and audio data corresponding thereto in parallelis sent to the audio processor 12.

During 2× speed playback, the amount of the audio data is equivalent totwenty-four channels, which is double the amount during 1× speedplayback. Since only sixteen channels of audio data can be embedded inone HD-SDI signal, the audio processor 12 divides the audio data to beoutputted to a LINK-A HD-SDI transmitter 13 and a LINK-B HD-SDItransmitter 14 that comply to dual-link HD-SDI.

FIGS. 7A to 7D show the audio data outputted from the ECC decoders 21-1,21-2 and the audio data outputted from the HD-SDI transmitters 13, 14.As shown in FIG. 7A, audio data that corresponds to the video data inthe odd-numbered fields, such as “audio1(800)”, “audio3(801)”,“audio5(801)”, “audio7(801)”, . . . is outputted from the ECC decoder21-1 to the audio processor 12.

As shown in PIG. 7B, audio data that corresponds to the video data inthe even-numbered fields, such as “audio2(801)”, “audio4(801)”,“audio6(801)”, “audio8(801)”, . . . is outputted from the ECC decoder21-2 to the audio processor 12 in parallel with the audio data from theECC decoder 21-1.

The audio processor 12 outputs the audio data from the ECC decoder 21-1to the HD-SDI transmitter 13 without changing the order and outputs theaudio data from the ECC decoder 21-2 to the HD-SDI transmitter 14, againwithout changing the order.

The HD-SDI transmitters 13, 14 embed a predetermined number of samplesof audio data into the video data of each field. For example, if thepredetermined number of samples is 801, as shown in FIG. 7C,“audio1(800)” is of 800 samples and short of one sample, and thereforethe HD-SDI transmitter 13 takes one sample (that is, “[s1]” in FIG. 7C)from the start of “audio3(801)” and embeds a total of 801 samples in thevideo data to be outputted.

Next, since this results in “audio3(801)” having 800 samples that isshort of one sample, one sample (that is, “[s2]” in FIG. 7C) is takenfrom the start of “audio5(801)” and a total of 801 samples are embeddedin the video data to be outputted. Since this in turn results in“audio5(801)” having 800 samples that is short of one sample, one sample(that is, “[s3]” in FIG. 7C) is taken from the start of the next audiodata (not shown) and a total of 801 samples are embedded in the videodata to be outputted. The same processing is then repeated thereafter.

As shown in FIG. 7D, since “audio2(801)” and “audio4(801)” each have 801samples, the HD-SDI transmitter 14 embeds such audio in the video datawithout adding a sample, but since the “audio6(800)” has 800 samples andis short of one sample, one sample (that is, “[s4]”in FIG. 7D) is takenfrom the start of the next audio data (not shown) and a total of 801samples are embedded in the video data to be outputted. The sameprocessing is then repeated thereafter.

However, if dual-link HD-SDI signals in which audio data has beenembedded in this way are outputted from the HD-SDI transmitters 13, 14,an apparatus that receives the dual-link HD-SDI signals (for example, avideo server used in a program production system) may not be able toreconstitute audio data that is consecutive in the original order.

FIG. 8 shows the audio data reconstituted in a receiving apparatus fromthe output of the HD-SDI transmitters 13, 14. At the receivingapparatus, audio data is reconstituted by alternately arranging theaudio data outputted from a LINK-A HD-SDI receiver and the audio dataoutputted from a LINK-B HD-SDI receiver. However, the audio datareconstituted in this way includes one sample [s1] (that is the same as[s1] shown in FIG. 7C) from the start of “audio3(801)” between“audio1(800)” and “audio2(801)”, one sample [s2] (that is the same as[s2] shown in FIG. 7C) from the start of “audio5(801)” between“audio3(801)” and “audio4(801)”, . . . . Therefore, the reconstituteddata has samples that are not in order of time and is not consecutive inthe original order.

It is desirable to easily reconstitute audio data consecutive in theoriginal order in a receiving apparatus, when a HDCAM SR® format VTRplays back video data with a field frequency of 59.94 Hz at 2× speed andtransmits data as a dual-link HD-SDI signal.

According to an embodiment of the present invention, there is provided adata output apparatus. The data output apparatus includes: a playbackunit and an audio processing unit. The playback unit plays back data at2× speed from a tape-shaped recording medium, on which is recorded videodata with a field frequency of 59.94 Hz and n channels (where n is aninteger in a range of 9 to 16, inclusive) of audio data with a samplingfrequency of 48 kHz where out of five consecutive fields, 800 samplesare recorded corresponding to one field and 801 samples are recordedcorresponding to each of the remaining four fields. Accordingly, theplayback unit plays back video data in odd-numbered fields and audiodata corresponding thereto and video data in even-numbered fields andaudio data corresponding thereto in parallel. The audio processing unitwrites the audio data corresponding to the odd-numbered fields and theaudio data corresponding to the even-numbered fields played back inparallel by the playback unit into a memory, reads out the audio datafrom the memory at 96 kHz in order of the corresponding fields, andoutputs the audio data to dual-link HD-SDI transmitters.

According to an embodiment of the present invention, there is provided adata output method. The data output method includes the steps of:

playing back data at 2× speed from a tape-shaped recording medium, onwhich is recorded video data with a field frequency of 59.94 Hz and nchannels (where n is an integer in a range of 9 to 16, inclusive) ofaudio data with a sampling frequency of 48 kHz where out of fiveconsecutive fields, 800 samples are recorded corresponding to one fieldand 801 samples are recorded corresponding to each of the remaining fourfields, by playing back video data in odd-numbered fields and audio datacorresponding thereto and video data in even-numbered fields and audiodata corresponding thereto in parallel;

writing the audio data corresponding to the odd-numbered fields and theaudio data corresponding to the even-numbered fields played back inparallel in the data playback step into a memory and reading out theaudio data from the memory at 96 kHz in order of the correspondingfields; and

outputting the audio data read out from the memory in the writing andreading step to dual-link HD-SDI transmitters.

The data output apparatus and data output method according to anembodiment of the present invention play back data at 2× speed byplaying back audio data corresponding to odd-numbered fields and audiodata corresponding to even-numbered fields out of n channels (where n isan integer in a range of 9 to 16, inclusive) of audio data with asampling frequency of 48 kHz in parallel corresponding to video datawith a field frequency of 59.94 Hz. Subsequently, such audio data iswritten in a memory, and the audio data is read from the memory at 96kHz in order of the corresponding fields. After this, the audio dataread from the memory is outputted to dual-link HD-SDI transmitters.

Accordingly, audio data consecutive in the original order is outputtedto the dual-link HD-SDI transmitters in the same way as shown in FIG. 4Bthat relates to playing back data at 1× speed.

By doing so, when a HDCAM SR® format VTR plays back video data with afield frequency of 59.94 Hz at 2× speed and transmits the video data asa dual-link HD-SDI signal, it is possible for a receiver to easilyreconstitute audio data consecutive in the original order.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing the number of recording samples of audiodata in each field when the field frequency is 59.94 Hz.

FIG. 2 is a diagram showing the recording positions of the video dataand audio data shown in FIG. 1 on a magnetic tape.

FIG. 3 is a block diagram showing an audio data output system whenplaying back data at 1× speed.

FIGS. 4A and 4B are diagrams showing audio data outputted from the ECCdecoder and HD-SDI transmitter shown in FIG. 3.

FIG. 5 is a diagram showing details of the channels of audio dataoutputted from the audio processor shown in FIG. 3.

FIG. 6 is a block diagram showing an audio data output system whenplaying back data at 2× speed.

FIGS. 7A to 7D are diagrams showing audio data outputted from the ECCdecoders and HD-SDI transmitters shown in FIG. 6.

FIG. 8 is a diagram showing the audio data reconstituted in a receivingapparatus from the output of the HD-SDI transmitters shown in FIG. 7.

FIG. 9 is a block diagram showing an audio data output system for 2×speed playback according to an embodiment of the present invention.

FIGS. 10A to 10J are diagrams showing write addresses and read addressesfor a memory shown in FIG. 9.

FIG. 11 is a diagram showing the relationship between the audio dataoutputted from the ECC decoders shown in FIG. 9 and the audio data readfrom the memory shown in FIG. 9.

FIG. 12 is a diagram showing details of the channels of audio dataoutputted from the audio processor shown in FIG. 9.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Preferred embodiments of the present invention will now be describedwith reference to the attached drawings. FIG. 9 is a block diagramshowing an output system for audio data when playing back data at 2×speed in an HDCAM SR® format VTR according to an embodiment of thepresent invention. Parts that are the same as in the configuration shownin FIG. 6 described above have been assigned the same referencenumerals.

The rotational speed of a rotating drum (not shown) that drives amagnetic tape TP is set at double the speed during playback at 1× speed.The signal read out from the magnetic tape TP at 2× speed by a playbackhead PB is divided at a switch 10 into signals from recording tracks fordata in odd-numbered fields (“picture1” and “audio1(800)”, “picture3”and “audio3(801)”, and “picture5” and “audio5(801)” shown in FIGS. 1 and2 described above) and signals from recording tracks for data ineven-numbered fields (“picture2” and “audio2(801)”, and “picture4” and“audio4(801)” shown in FIGS. 1 and 2 described above) and such signalsare written into a cache memory 11-1 and a cache memory 11-2,respectively.

The signals written into the cache memories 11-1, 11-2 are convertedinto 1× speed signals by reading the signals from the cache memories11-1, 11-2 at one half of the rate used when writing the signals.

The 1× speed signals from the cache memories 11-1, 11-2 are subjected towave-shaping and decoding processes in decoding units 20-1, 20-2,respectively, and are then subjected to error correction in ECC decoders21-1, 21-2, respectively.

Audio data that has been subjected to error correction is outputted fromthe ECC decoders 21-1, 21-2 to an audio processor 1. By doing so, audiodata that has been played back at 2× speed by playing back video data ofodd-numbered fields and audio data corresponding thereto and video dataof even-numbered fields and audio data corresponding thereto in parallelis sent to the audio processor 1.

Start signals ST1, ST2 (i.e., signals showing the start of data in eachfield) read from start positions of the recording tracks for data ineach field and “5-field” IDs (that is, IDs that identify whether thenumber of samples in the audio data is 800 or 801) ID1, ID2 read outfrom positions before the recording positions of audio data on therecording tracks for the data in each field are also outputted from theECC decoders 21-1, 21-2 to the audio processor 1.

The audio processor 1 includes a memory 2 and a memory controller 3 thatcontrols the memory 2. The memory controller 3 uses the start signalsST1, ST2 and the “5-field” IDs ID1, ID2 to generate the write addressesused when writing audio data from the ECC decoders 21-1, 21-2 into thememory 2 and writes the audio data from the ECC decoders 21-1, 21-2 intothe regions with such write addresses.

FIGS. 10A to 10H show the write addresses in the memory 2 generated bythe memory controller 3. During a given field period EC1, after thestart signal ST1 (see FIG. 10A) has been sent from the ECC decoder 21-1,when a “5-field” ID ID1 (see FIG. 10B) with the value 0 is sent from theECC decoder 21-1, write addresses 0 to 799 (see FIG. 10D) for writingaudio data “audio1(800)” (see FIG. 10C) with 800 samples from the ECCdecoder 21-1 are generated.

Also, during the given field period FC1, after the start signal ST2 (seeFIG. 10E) has been sent from the ECC decoder 21-2, when a “5-field” IDID2 (see FIG. 10F) with the value 1 is sent from the ECC decoder 21-2,write addresses 800 to 1600 (see FIG. 10H) for writing audio data“audio2(801)” (see FIG. 10G) with 801 samples from the ECC decoder 21-2are generated.

Subsequently, during the next field period FC2, after the start signalST1 (see FIG. 10A) has been sent from the ECC decoder 21-1, when a“5-field” ID ID1 (see FIG. 10B) with the value 2 is sent from the ECCdecoder 21-1, write addresses 1601 to 2401 (see FIG. 10D) for writingaudio data “audio3(801)” (see FIG. 10C) with 801 samples from the ECCdecoder 21-1 are generated.

Also, during the given field period FC2, after the start signal ST2 (seeFIG. 10E) has been sent from the ECC decoder 21-2, when a “5-field” IDID2 (see FIG. 10F) with the value 3 is sent from the ECC decoder 21-2,write addresses 2402 to 3202 (see FIG. 10H) for writing audio data“audio4(801)” (see FIG. 10G) with 801 samples from the ECC decoder 21-2are generated.

Subsequently, during the next field period FC3, after the start signalST1 (see FIG. 10A) has been sent from the ECC decoder 21-1, when a“5-field” ID ID1 (see FIG. 10B) with the value 4 is sent from the ECCdecoder 21-1, write addresses 3203 to 4003 (see FIG. 10D) for writingaudio data “audio5(801)” (see FIG. 10C) with 801 samples from the ECCdecoder 21-1 are generated.

Also, during the given field period FC3, after the start signal ST2 (seeFIG. 10E) has been sent from the FCC decoder 21-2, when a “5-field” ID1D2 (see FIG. 10F) with the value 0 is sent from the ECC decoder 21-2,write addresses 4004 to 4803 (see FIG. 10H) for writing audio data“audio6(800)” (see FIG. 10G) with 800 samples from the ECC decoder 21-2are generated.

Subsequently, during the next field period FC4, after the start signalST1 (see FIG. 10A) has been sent from the ECC decoder 21-1, when a“5-field” ID ID1 (see FIG. 10B) with the value 1 is sent from the ECCdecoder 21-1, write addresses 4804 to 5604 (see FIG. 10D) for writingaudio data “audio7(801)” (see FIG. 10C) with 801 samples from the ECCdecoder 21-1 are generated.

Also, during the given field period FC4, after the start signal ST2 (seeFIG. 10E) has been sent from the ECC decoder 21-2, when a “5-field” IDID2 (see FIG. 10F) with the value 2 is sent from the ECC decoder 21-2,write addresses 5605 to 6405 (see FIG. 10H) for writing audio data“audio8(801)” (see FIG. 10G) with 801 samples from the ECC decoder 21-2are generated.

After this, the same processing is repeated. By doing so, consecutiveaudio data “audio1(800)”, “audio2(801)”, “audio3(801)”, “audio4(801)”“audio5(801)”, “audio6(800)”, “audio7(801)” “audio8(801)”, . . . arewritten into the regions 0 to 799, 800 to 1600, 1601 to 2401, 2402 to3202, 3203 to 4003, 4004 to 4803, 4804 to 5604, 5605 to 6405, . . .representing consecutive write addresses in the memory 2.

The memory controller 3 reads the audio data that was written into thememory 2 as described above at double (that is, 96 kHz) the rate duringwriting to the memory 2 in order of the fields corresponding togenerated consecutive read addresses 0 to 799, 800 to 1600, 1601 to2401, 2402 to 3202, 3203 to 4003, 4004 to 4803, 4804 to 5604, 5605 to6405, . . . .

FIGS. 10I and 10J are diagrams showing the read addresses and data readfrom the memory 2. Audio data with a sampling frequency of 96 kHz thatis consecutive in the original order, that is, “audio1(800)”,“audio2(801)”, “audio3(801)”, “audio4(801)”, “audio5(801)”,“audio6(800)”, . . . is read out.

FIG. 11 shows the relationship between the audio data outputted from theECC decoders 21-1, 21-2 and the audio data read out from the memory 2 byillustrating FIGS. 10C, 10G, and 10J out of FIGS. 10A to 10J. In spiteof the audio data corresponding to the odd-numbered fields and the audiodata corresponding to the even-numbered fields being outputted inparallel from the ECC decoders 21-1, 21-2, audio data that is arrangedso as to be consecutive in the original order is read out from thememory 2 (however, such audio data has double the sampling rate at 96kHz).

The audio processor 1 outputs such audio data to the HD-SDI transmitters13, 14 in the order of “audio1(800)”, “audio2(801)”, “audio3(801)”,“audio4(801)”, “audio5(801)”, “audio6(800)”, . . . .

FIG. 12 shows details of the channels of audio data outputted from theaudio processor 1. Here, it is possible to embed audio data for sixteenchannels in each of the LINK-A and LINK B HD-SDI signals. The HD-SDItransmitters 13, 14 are each provided with eight input terminals I1 toI8 for inputting sixteen channels of audio data. However, since theaudio data outputted from the audio processor 1 has double the dataamount due to the sampling frequency of 96 kHz, the number of channelsthat can be embedded in the LINK-A and LINK B HD-SDI signals is half ofsuch number, i.e., eight.

Out of the audio data read out from the memory 2, the audio processor 1outputs data on a same channel out of the first channel to the eighthchannel consecutively to the input terminals I1 to I8 of the HD-SDItransmitter 13 and outputs data on a same channel out of the ninthchannel to the twelfth channel consecutively to the input terminals I1to I4 out of the input terminals I1 to I8 of the HD-SDI transmitter 14.

That is, in a given sampling period SC1, the audio processor 1 outputsthe following audio data to the input terminals I1 to I8 of the HD-SDItransmitter 13 and the input terminals I1 to I4 of the HD-SDItransmitter 14.

-   -   ch1_0 that is part of the data on channel ch1 and ch1_1 that is        data following thereafter are outputted to the input terminal I1        of the HD-SDI transmitter 13.    -   ch2_0 that is part of the data on channel ch2 and ch2_1 that is        data following thereafter are outputted to the input terminal I2        of the HD-SDI transmitter 13.    -   ch3_0 that is part of the data on channel ch3 and ch3_1 that is        data following thereafter are outputted to the input terminal I3        of the HD-SDI transmitter 13.    -   ch4_0 that is part of the data on channel ch4 and ch4_1 that is        data following thereafter are outputted to the input terminal I4        of the HD-SDI transmitter 13.    -   ch5_0 that is part of the data on channel ch5 and ch5_1 that is        data following thereafter are outputted to the input terminal I5        of the HD-SDI transmitter 13.    -   ch6_0 that is part of the data on channel ch6 and ch6_1 that is        data following thereafter are outputted to the input terminal I6        of the HD-SDI transmitter 13.    -   ch7_0 that is part of the data on channel ch7 and ch7_1 that is        data following thereafter are outputted to the input terminal I7        of the HD-SDI transmitter 13.    -   ch8_0 that is part of the data on channel ch8 and ch8_1 that is        data following thereafter are outputted to the input terminal I8        of the HD-SDI transmitter 13.    -   ch9_0 that is part of the data on channel ch9 and ch9_1 that is        data following thereafter are outputted to the input terminal I1        of the HD-SDI transmitter 14.    -   ch10_0 that is part of the data on channel ch10 and ch10_1 that        is data following thereafter are outputted to the input terminal        I2 of the HD-SDI transmitter 14.    -   ch11_0 that is part of the data on channel ch11 and ch11_1 that        is data following thereafter are outputted to the input terminal        I3 of the HD-SDI transmitter 14.    -   ch12_0 that is part of the data on channel ch12 and ch12_1 that        is data following thereafter are outputted to the input terminal        I4 of the HD-SDI transmitter 14.

In the next sampling period SC2, the audio processor 1 outputs thefollowing audio data to the input terminals I1 to I8 of the HD-SDItransmitter 13 and the input terminals I1 to 14 of the HD-SDItransmitter 14.

-   -   data ch1_2 that follows data ch1_1 on channel ch1 and data ch1_3        that follows thereafter are outputted to the input terminal I1        of the HD-SDI transmitter 13.    -   data ch2_2 that follows data ch2_1 on channel ch2 and data ch2_3        that follows thereafter are outputted to the input terminal I2        of the HD-SDI transmitter 13.    -   data ch3_2 that follows data ch3_1 on channel ch3 and data ch3_3        that follows thereafter are outputted to the input terminal I3        of the HD-SDI transmitter 13.    -   data ch4_2 that follows data ch4_1 on channel ch4 and data ch4_3        that follows thereafter are outputted to the input terminal I4        of the HD-SDI transmitter 13    -   data ch5_2 that follows data ch5_1 on channel ch5 and data ch5_3        that follows thereafter are outputted to the input terminal I5        of the HD-SDI transmitter 13.    -   data ch6_2 that follows data ch6_1 on channel ch6 and data ch6_3        that follows thereafter are outputted to the input terminal I6        of the HD-SDI transmitter 13.    -   data ch7_2 that follows data ch7_1 on channel ch7 and data ch7_3        that follows thereafter are outputted to the input terminal I7        of the HD-SDI transmitter 13.    -   data ch8_2 that follows data ch_1 on channel ch8 and data ch8_3        that follows thereafter are outputted to the input terminal I8        of the HD-SDI transmitter 13.    -   data ch9_2 that follows data ch9_1 on channel ch9 and data ch9_3        that follows thereafter are outputted to the input terminal I1        of the HD-SDI transmitter 14.    -   data ch10_2 that follows data ch10_1 on channel ch10 and data        ch10_3 that follows thereafter are outputted to the input        terminal I2 of the HD-SDI transmitter 14.    -   data ch11_2 that follows data ch11_1 on channel ch11 and data        ch11_3 that follows thereafter are outputted to the input        terminal I3 of the HD-SDI transmitter 14.    -   data ch12_2 that follows data ch12_1 on channel ch12 and data        ch12_3 that follows thereafter are outputted to the input        terminal I4 of the HD-SDI transmitter 14.

Subsequently, in the same way, audio data on the channels ch1 to ch8 isconsecutively outputted in each sampling period to the input terminalsI1 to I8 respectively of the HD-SDI transmitter 13 and audio data on thechannels ch9 to ch12 is consecutively outputted in each sampling periodto the input terminals I1 to I4 respectively of the HD-SDI transmitter14.

In this way, audio data consecutive in the original order is outputtedto the HD-SDI transmitters 13, 14 from the audio data output system inthe same way as shown in FIG. 4B where data is played back at 1× speed.

By doing so, an apparatus that receives dual-link HD-SDI signalsoutputted from the HD-SDI transmitters 13, 14 (for example, a videoserver used in a program production system) will be able to easilyreconstitute audio data consecutive in the original order. Note that thesampling frequency of the audio data can be reconstituted from 96 kHz to48 kHz as necessary using a memory or the like provided for suchreceiving apparatus.

According to an embodiment of the present invention, the rotationalspeed of the rotating drum is doubled compared to playback of data at 1×speed. The signal read out at 2× speed from the magnetic tape TP isdivided using the switch 10 into a signal for odd-numbered fields and asignal for even-numbered fields, and the cache memories 11-1, 11-2convert the signals to a 1× speed signal, thereby playing back data at2× speed. Alternatively, it is also possible to keep the rotationalspeed of the rotating drum at the same speed as during 1× speedplayback, to double the number of playback heads, and to simultaneouslyread a signal for odd-numbered fields with one playback head and asignal for even-numbered fields with another playback head.

According to an embodiment of the present invention, HDCAM SR® format isused. However, other VTR formats than HDCAM SR® format can be usedsimilarly as long as video data is recorded with a field frequency of59.94 Hz and n channels (where n is an integer in a range of 9 to 16,inclusive) of audio data with a sampling frequency of 48 kHz is recordedso that out of five consecutive fields, 800 samples correspond to onefield and 801 samples correspond to the remaining four fields.

It should be understood by those skilled in the art that variousmodifications, combinations, sub-combinations and alterations may occurdepending on design requirements and other factors insofar as they arewithin the scope of the appended claims or the equivalents thereof.

1. A data output apparatus, comprising: a playback unit carrying outplayback of data at 2x speed from a tape-shaped recording medium, onwhich has been recorded video data with a field frequency of 59.94 Hzand n channels (where n is an integer in a range of 9 to 16, inclusive)of audio data with a sampling frequency of 48 kHz where out of fiveconsecutive fields, 800 samples are recorded corresponding to one fieldand 801 samples are recorded corresponding to each of the remaining fourfields, by playing back video data in odd-numbered fields and audio datacorresponding thereto and video data in even-numbered fields and audiodata corresponding thereto in parallel; and an audio processing unitwriting the audio data corresponding to the odd-numbered fields and theaudio data corresponding to the even-numbered fields played back inparallel in the playback unit into a memory, reading out the audio datafrom the memory at 96 kHz in order of the corresponding fields, andoutputs the audio data to dual-link HD-SDI transmitters.
 2. The dataoutput apparatus according to claim 1, wherein the audio processing unitoutputs the audio data read from the memory to the dual-link HD-SDItransmitters so that data on a same channel is consecutive.
 3. The dataoutput apparatus according to claim 2, wherein out of the audio dataread out from the memory, the audio processing unit outputs data on afirst channel to an eighth channel to a dual-link HID-SDI LINK-Atransmitter so that data on a same channel is consecutive and outputsdata on a ninth channel and subsequent channels to a dual-link HD-SDILINK-B transmitter so that data on a same channel is consecutive.
 4. Thedata output apparatus according to claim 2, wherein the playback unitplays back video data and twelve channels of audio data that have beenrecorded according to HDCAM SR® format, and out of the audio data readout from the memory, the audio processing unit outputs data on a firstchannel to an eighth channel to a dual-link HD-SDI LINK-A transmitter sothat data on a same channel is consecutive and outputs data on a ninthchannel to a twelfth channel to a dual-link HD-SDI LINK-B transmitter sotat data on a same channel is consecutive.
 5. A data output method,comprising the steps of: carrying out playback of data at 2x speed froma tape-shaped recording medium, on which has been recorded video datawith a field frequency of 59.94 Hz and n channels (where n is an integerin a range of 9 to 16, inclusive) of audio data with a samplingfrequency of 48 kHz where out of five consecutive fields, 800 samplesare recorded corresponding to one field and 801 samples are recordedcorresponding to each of the remaining four fields, by playing backvideo data in odd-numbered fields and audio data corresponding theretoand video data in even-numbered fields and audio data correspondingthereto in parallel; writing the audio data corresponding to theodd-numbered fields and the audio data corresponding to theeven-numbered fields played back in parallel in the data playback stepinto a memory and reading out the audio data from the memory at 96 kHzin order of the corresponding fields; and outputting the audio data readout from the memory in the writing and reading step to dual-link HD-SDItransmitters.
 6. The data output method according to claim 5, whereinthe audio data read from the memory is outputted to the dual-link HD-SDItransmitters in the outputting step so that data on a same channel isconsecutive.
 7. The data output method according to claim 6, wherein outof the audio data read out from the memory, data on a first channel toan eighth channel is outputted to a dual-link HD-SDI LINK-A transmitterso tat data on a same channel is consecutive and data on a ninth channeland subsequent channels is outputted to a dual-link HD-SDI LINK-Btransmitter so that data on a same channel is consecutive, in theoutputting step.
 8. The data output method according to claim 6, whereinvideo data and twelve channels of audio data that have been recordedaccording to HDCAM SR® format are played back in the playback step, andout of the audio data read out from the memory, data on a first channelto an eighth channel is outputted to a dual-link HD-SDI LINK-Atransmitter so that data on a same channel is consecutive and data on aninth channel to a twelfth channel is outputted to a dual-link HD-SDILINK-B transmitter so tat data on a same channel is consecutive, in theoutputting step.